1. Field of the Invention
The present invention relates to aircraft turbojet engines, and in particular to neat protective linings provided inside not parts of the engine such as an afterburner passage, or a transition passage situated between the circular part of the hot flow duct downstream of the turbine and a bi-dimensional nozzle, or even a wall of a main combustion chamber.
2. Summary of the Prior Art
It is known for these various parts of a turbo-engine to form the neat protective linings from tiles placed in side by side or overlapping relation to form rings which are themselves arranged axially end to end to produce a cylindrical heat protective structure which is disposed inside the passage to be protected. This structure is made of a material able to withstand very high temperatures, and is arranged so as to allow the flow of pressurized air between the structure and the wall of the passage to be protected, the pressurized air being relatively colder than that flowing inside the said structure.
French Patent No. 2 567 250 describes a combustion chamber structure in which the hot, structural, wall receives tiles forming the cold wall, the tiles having their upstream edge engaged in a groove of the not wall, whereas their downstream edge has inwardly a folded part which engages in a second circular groove of the hot wall. This arrangement requires a retaining O-ring on the downstream part.
U.S. Pat. No. 4,614,082 describes a heat protective related structure in which the tiles also have hooks cooperating with grooves, but require radial pins to hold them in position.
U.S. Pat. No. 4,480,436 describes a heat protective lining for a combustion chamber formed by panels fitting together circularly by means of tongues and grooves, and having an upstream groove and a downstream groove cooperating with hook-shaped tongues of the cold wall on which the panels slide.
Here again it is sought to make a double wall in a combustion chamber so that it is possible to effect a ventilation flow between the two walls for the purpose of cooling the outer wall.